Currently, after a conventional terminal, such as a computer system, is started, almost all of its functions are made usable, including networking, video playing, and plugging and pulling a Universal Serial Bus (USB) device at any time. However, in some cases, while a computer is used, not all the functions of the computer system are necessary. For example, in a case where the computer is used as a teaching-purpose computer or a student-used computer, a teacher may ask students to simply perform a particular operation or accomplish a particular task on a local hard disk. In this case, it is desirable to disable some of the functions of the computer system, for example, to prevent the students from using the computer to browse web pages, chat, watch movies or copying their software and games to the computer via a card reader to perform other operations, such that the students will not be distracted from their task.
In the prior art, some functions can be disabled using some software. For example, in a net bar, a user may be prohibited from using some functions of a computer, e.g., from using a disc drive. However, this solution is software based. Although it appears that the user cannot use the disabled functions, the devices that actually implement these functions (such as the disc drive) are not powered off, i.e., they are still connected with the main board of the computer and their power supplies are not cut off. Thus, there is a waste of energy, which does not comply with the recent low-carbon environmental preservation requirements.